The
XmbTextPerCharExtents, XwcTextPerCharExtents and Xutf8TextPerCharExtents
functions return the text dimensions of each character of the specified
text, using the fonts loaded for the specified font set. Each successive
element of ink_array_return and logical_array_return is set to the successive
character's drawn metrics, relative to the drawing origin of the string
and one rectangle for each character in the supplied text string. The number
of elements of ink_array_return and logical_array_return that have been
set is returned to num_chars_return.

Each element of ink_array_return is
set to the bounding box of the corresponding character's drawn foreground
color. Each element of logical_array_return is set to the bounding box
that provides minimum spacing to other graphical features for the corresponding
character. Other graphical features should not intersect any of the logical_array_return
rectangles.

Note that an XRectangle represents the effective drawing
dimensions of the character, regardless of the number of font glyphs that
are used to draw the character or the direction in which the character
is drawn. If multiple characters map to a single character glyph, the dimensions
of all the XRectangles of those characters are the same.

When the XFontSet
has missing charsets, metrics for each unavailable character are taken
from the default string returned by XCreateFontSet so that the metrics
represent the text as it will actually be drawn. The behavior for an invalid
codepoint is undefined.

If the array_size is too small for the number of
characters in the supplied text, the functions return zero and num_chars_return
is set to the number of rectangles required. Otherwise, the functions return
a nonzero value.

If the overall_ink_return or overall_logical_return argument
is non-NULL, XmbTextPerCharExtents, XwcTextPerCharExtents and Xutf8TextPerCharExtents
return the maximum extent of the string's metrics to overall_ink_return
or overall_logical_return, as returned by XmbTextExtents, XwcTextExtents
or Xutf8TextExtents.

The function Xutf8TextPerCharExtents is an XFree86
extension introduced in XFree86 4.0.2. Its presence is indicated by the macro
X_HAVE_UTF8_STRING.